Constant delivery pump



Oct. 14, 1952 M. R. sHEl-:N l-:rAL

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CONSTANT DELIVERY PUMP Y Oct. 14, 1952 Filed om. e, 194s '7 Sheets-Sheet6 Patented Oct. 14, 1952 UNITED s'rA'res le'rilvr trice CONSTANTDELIVERY PUMP Milton Roy Sheen, deceased, late of Glenside, Pa.,

by Emma Elizabeth Sheen, coexecutor, Glenside, Pa., and Robert T. Sheen,Wyndmoor, Pa., and Royal Bartlett Saalfrank, Gulfport, Fla.; said RobertT. Sheen and said Saalfrank asn signors to Milton Roy Company, ChestnutHill, Pa., a corporation of Pennsylvania Application October 6, 19513,Serial No. 53,122

(Cl. 103--38l Claims. 1

The present invention relates to a constant delivery pump.

The present application is a continuation in part of our applicationSerial No. 778,316, iiled October 7, 1947, now abandoned, for ConstantDelivery Pump, and supercedes such earlier application.

A purpose of the invention is to permit the use of constant deliverypumps for extremely precise feeding of chemicals and the like in whichsubstantially no change in the flow curve is to be permitted, and inwhich the high precision in the delivery of liquids over a wide deliveryrange and in some cases down to unprece dented small delivery quantitiesare required.

A further purpose is to permit very accurate change of the strokes of aplurality of pumps operating in unison for constant delivery purposes(that is, with common inlet and common discharge) while such pumps arein operation, with or without variationv in the speed of the drive, andwith intermittent or continuous pumping.

A further purpose is to accomplish adjustment of the stroke of eachpiston or other pumping element which maintains a directly proportionalrelationship between the motion of the adjustment and the stroke of theelement at the particular adjustment over the entire range of theadjustment so that a dial or other indication of adjustment willdirectly indicate stroke, and so that the adjustment can be accomplishedby a remote control in respect to determination of the volume pumped.

A further purpose is to` adjust the position of adjustment supportmechanically connected to the driving connections for each pumpingelement along a line which maintains the same angular relation withrespect to each pumping element for any adjustment at at least onecorrespending position in the stroke of all pumping elements.

A further purpose is to adjust the stroke of each pumping element whilemaintaining an invariable relation between the speed oi each element atone part `of the stroke and the speed at every other part of the strokeso that a dischargeV curve for the constant delivery pump which isuniform for one adjustment will be uniform for all other adjustments.

A further purpose is to permit the required out-of-phase relation of thetwo reciprocating pumps in a constant delivery system to be maintainedby a cam acting on crossheads, preferably through connecting rods andcrank blocks.

A :further purpose is to maintain a constant throw on the crank blocks,but to vary the positions of pivotal connection between the crank blocksand the crossheads to control the stroke.

Further purposes appear in the specication and in the claims.

In the prior art constant delivery pumps have been intended primarilyfor comparatively large volumes in which slight lack of uniformity oidelivery can be tolerated. With the increased demands for precisefeeding of liquids, especially chemicals, for treatment of materials inprocess, a demand lhas arisen for high uniformity and constancy ofdelivery with permissible wide variation. The present invention isintended primarily to meet the demand for an extremely uniform deliverywith practically no change in the delivery curve, while at the same timepermitting very wide variation and operation at unbelievably low levels.For example in the pump of the present invention effective operation canbe maintained with delivery of as little as a few cubic centimetersl perhour, and the invention can likewise be applied. to delivery of only afew cubic centimeters per day. Notwithstanding such low delivery levelsand the possible requirementior wide variation, while the pump isoperating it will maintain a precisely accurate andvconstan't delivery,while at the same time permitting instantaneous change in the deliveryduring operation.

In many prior art patents of the constant delivery pump type dimcultyhas been encountered in changing the stroke during operation, and insome the possibility has existed that the stroke will be different inthe two pumps.

In accordance with the present invention not only can the speed `ofdrive be changed by the use of a variable speed motor, but also thestroke of both pumps can be changed in unison during operation. Likewiseof course the operation can be continuous or intermittent in response toany suitable control which will start and stop or vary the speed of thedrive, as well known in the art.

In the drawings a few only of the various embodiments of the inventionhave been illustrated, choosing the forms shown from the standpoints ofconvenience in illustration, satisfactory operation and cleardemonstration of the principles involved.

Figure 1 is a top plan view of our novel constant delivery pumpmechanism.

Figure 2 is a horizontal section of Figure 1 taken on the line 2-2 ofFigure 3.

Figure 3 is a longitudinal vertical section taken in the line 3--3 ofFigure 2.

Figure 4 is a transverse vertical section taken on the line 4-4 ofFigure 3.

Figure 5 is a fragmentary perspective illustrating the connecting rods,crank blocks and crossheads.

Figure 6 is an exploded perspective view illustrating the crank blocks,the sliding bearings of the connecting rod and the crossheads and thecrosshead adjustment.

Figures '7 and '7a are views similar to Figure 1 but illustratingmodifications.

Figure 8 is a graph useful in explaining the invention.

Figure 9 is a longitudinal section corresponding to Figure 3 showing avariation in the constant delivery pump mechanism.

Figure 10 is a transverse section of Figure 9 on I..

the line Ill-l0.

Figure 11 is a diagrammatic top plan view showing the inlet and outletconnections to the pump units of the constant delivery pump.

Figure 12 is a fragmentary longitudinal section showing a bellowsreplacing a piston as the pumping element.

In the drawings like numerals refer to like parts throughout.

Describing in illustration but not in limitation and referring to thedrawings:

In the prior art efforts have been made to regulate the stroke of apiston or other reciprocating pump with the purpose of obtainingadjustment of the discharge. The constructions used for such purposeshave normally adjusted along an arc or rocker arm, and have not beensuitable for application to constant delivery pumps of high accuracy. Insuch prior art constructions the motion imparted by the adjustment hasnot produced a stroke adjustment directly proportional to the adjustingmotion. This has necessitated the use of non-uniform graduations on adial indicating adjustment, if the dial is also to indicate stroke ordischarge, and has made it impossible to change the adjustment uniformlyby remote control or otherwise for the purpose of obtaining proportionalchange in stroke. If such prior art constructions are applied toconstant delivery pumps it is necessary to make elaborate calculationsor employ special curves in changing adjustments.`

Such prior art connecting and adjusting structures have presented afurther serious difficulty. While it is possible to obtain a straightline curve by placing two or more pumps having a common inlet and acommon discharge properly out of phase, the constant delivery obtainedfrom such prior art adjustment devices has remained constant only at oneadjustment position. Every time the adjustment is changed, the relationof the speed of the piston or other pumping element at one portion ofthe stroke to the speed at other portions of the stroke has changed,with resultp ing introduction of errors into the discharge Curve.

ent invention is that the motion of the adjustment is directlyproportional to the stroke of the piston or other pumping element aschanged by the adjustment, and this condition obtains throughout theentire range of adjustment. Thus during adjustment, the adjustmentsupport maintains the same angular relation with respect to each pumpingelement for any adjustment at at least one corresponding position in thestroke of all pumping elements.

Furthermore, in the adjustment of the present invention, an invariablerelation is maintained between the speed of each element at one part ofthe stroke and the speed at every other part of the stroke. Thusalthough the discharge varies with the adjustment, the uniformity of thedischarge curve is the same for all adjustments and there is notendency, as in the prior art, for the relative instantaneous speed ofthe piston at some one portion of the stroke to change with respect tothat at some other portion of the stroke when the stroke is changed.

Power is applied to the mechanism through any suitable drive on shaft 20(Figure 3) in suitable bearings mounted on housing 2|. A pinion 22 onthe drive shaft meshes with a speed reduction train suitably consistingof a gear 23 on shaft 24 in suitable bearings in the housing andcarrying a pinion 25 intermeshing with a gear 26 on shaft 21 supportedon bearings in the housing, and carrying a pinion 28 intermeshing with agear 3D on shaft 3| provided with suitable bearings supported on thehousing. The shaft 3| carries a worm 32 which meshes with a worm wheel33 on stud shaft 34 which is mounted at one end in a journal bearing 35on a removable end plate 36 of the housing, and at the other end isprovided with an antifriction bearing 31 mounted on plate 38 and held byretainer 40. A removable cap 4| closes the end.

On the stud shaft 34 and turning with the worm wheel 33 is a cam 42 ofany suitable character, here shown as being a barrel cam having a track43 on the outer circumference 44.

On opposite sides and so positioned with respect to the track of the camthat they are constantly at diametrically opposite positions in thecycle of the pump, followers 45 and 46 are provided which constantlyride the cam slot and transmit the motion of the cam slotlongitudinally. The respective followers are suitably rollers which arerotatably supported on studs attached to connecting rods 41 and 48guided at the bottom at 5U and 5| near the two ends, and guided andsupported at the top at 52 and `53. As illustrated the respective guidesare provided with ways 54 and the connecting rods are provided withslides 55 which cooperate with the ways so as to provide guiding forreciprocation.

The slide bearings are supported by the sidewalls of the housing asshown.

At opposite ends the connecting rods carry followers 56 and 51, suitablyin the form of rollers mounted ,on studs, and the followers intermeshwith slots 58 in crank blocks 63 and The crank blocks are each pivotedon a common axis at 62 on bearings 63 in the housing, the bearings andpivots being suitably located above the slots of the crank blocks sothat the crank blocks swing back and forth pendulum fashion below thepivots.

On the opposite side of each crank block is a slot 64 paralleling theslot 58, and providing guiding wayssfor'follower rollers 65 mountedlonsliding blocks 66 and B1 which are guidedby vertical ways 68incrossheads 1 and 'II.V ,The sliding blocks 66 and 61 carry atttheiryupper ends T-shaped heads 12 which interlock with slots 131 on theopposite sides of a vertical adjustment block 14 which forms a nut foran adjustment screw 'l5 mounted on a, bearing 'I8 in the top of thehousing. .The adjustment screw 15 is suitably rotated by a handley 11 ona shaft 18' which carries a worm 80 gearing with a worm wheel 8l on theshaft of adjustment screw 15. Likewise atl thetop of the screw 15 isindicating gearing 83 for the stroke adjustment which includes a fastand slow clock drive ofv conventional character rotating a coarseadjustment hand 84 and a ilne adjustment'hand 'un'der a dial BB.

The adjustment block 14.1` is held against longitudinal movement and isguided in vertical adjustment by guides 81 supported on the housing. Itwill'be evident thatv the T-shaped head 12 slides in the slots 13 withthe motion of the crosshead.

The crossheads 10 and 1I are guided' in ways 88 extendinglongitudinally, and at their forward ends carry lugs 90 which receiveand retain push rods 9| having sliding bearings 92 and removablyconnected at 93 to a piston 94 oi a pump 95. There are two pumps side byside with their pistons parallel and directed in the same direction.While each pump may be of `any suitable reciprocating type, it willpreferably be of the character shown in Milton Roy Sheens United StatesPatentsl Nos. 2,263,429 and 2,367.893, having a cylinder Si?. an inletport 91, inlet check valves 98 and IUI) in series and connected by apassage IBI, outlet check valves ii and ll in series and connected by apassage |04 and an outlet port |05. Therespective check valves may allbe of ball type, inspected through a cover plate |06.

In operation power supplied through the main shaft 2li is transmittedthrough the speed reduction 22e, 23, 25, 2t, 2S, to to the worm 32 andworm wheel 33 for rotating the cam 42; As the cam iii turns itreciprocates at each side-one of the connecting rods 41, 48 through thecam follower Alt, the connecting rod positions being-such that each'pump is always at the opposite portion of vthe cycle, one pump being onsuction when the other is on compression, so as to maintain a constantdelivery.

Each of the connecting rods 41, 48 operates independently and as soon asthe motion is transmittedlto the connecting rods further motion isentirely Vindependent except for the adjustment of the adjustment block,which takes place on both sides of the mechanism in unison.

Each connecting rod through its follower swings one of the crank blocks6D, lil through a pendulum-like stroke which is determined by the throwof the cam 42. Each of the crank blocks te, lil has a slot whichinterconnects with the followerroller S5 on one of theA sliding blocks,

vwhich, is accordingly caused 'to 'slide back and i vforth throughavariant stroke depending upon its vertical position and the point of'engagement of its roller follower with the slot ofthe crank block. Thevertical position of thel sliding block is determined bythe adjustmentblock and adjustment screw engaging with the T-head` on the slidingblock.

As the-sliding blocks move vertically theyare supported and guided inthe vertical slots of the orosshcads 10, 'Il andas-they are reciprncatedby themoton of the followers; they carry with them theL reciprocationof. the crossheads, and correspondingly the motion of the pump pistons.

In order to permit slight angular adjustment ofthe crossheads in theirways 88, the crossheads and both ways are arcuately formed as shown at|01. f.

Where it is desired to shorten the piston stroke, the screw 'I5 ismanipulated so as to raise the adjustment block, thus bringing theengagement of the roller follower on the sliding block closer to'therocking center of. the crank block. Likewise for lengthening the stroke,the adjustment block will be lowered.

It will be understood of course that the electric driving motor whichoperates the drive shaft 2t will be controlled in any suitable mannervto turn it off and on or to vary its speed if required. The controlmechanism can of course be a remote control as well known in the art.Likewise the stroke can be varied by a remote control which will operateon the adjustment shaft 18. This is suggested in Figure 7 by a remotecontrol electric motor |68 which is shown with its speed reducer Idd tomanipulate the shaft 18 in response to the operation of any well knownremote control mechanism, and in Figure '7i by a pneumatic cylinder IIilhaving a remote pneumatic `connection III acting on a piston II2 havinga rod H3 directly connected to the adjustnient block I4 (omitting thescrew 15) and opposed by a spring l I4.

In the preferred embodiment shown the main drive operates a speedreduction which in turn drives a cam and the cam through opposite con'-necting rods swings crank blocks which in turn move the pump pistoncrossheads through sliding blocks, the sliding blocks being themselvesadjusted in unison.

It will be understood, however, that other forms of cam, otherinterconnections between the cam and the vcrossheads and otheradjustments of the crosshead strokes may be used to obtain part of theadvantage of the invention, aswell known. Y

Since the device of the invention in many cases will be used forchemicals, it will be evident that a liquid seal maybe introduced at H0around the outer ends of the pistons if necessary in the handling ofparticular chemicals.

Figure 8 illustrates in developed' diagrammatic form cam angle, asabscissae and stroke on both pumps as ordinate. The pumping stroke H5 onone pump overlaps the pumping stroke IIB of the other pump by an amountII1 which maintains constancy of discharge notwithstanding a lag inseating of the valves and reduces the pressure angle of the cam.

Figures 9 and lo illustrate a variation applying` the general principlesof the invention to a structure of somewhat difierent design, comingbroadly withinour invention, although some fea-- tures shown are thesole inventionof one of us.

Figure 9 shows the structure for operating one piston, and it will beunderstood that the structure for operating the other piston or pistonswill be identical vexcept that it operates from another cam trackpreferably located on the opposite side of the cam. The piston 94 isplvotally connected at 25 at an intermediate point i on an adjustmentrocker l2I which pivotally connects at E22 to an adjustment support orblock 'M which is common' to the other rockerl or rockers forthe otherpiston-or pistons, which-are suitably located on a common axis with thepivot |22.' The adjustment support 14 is manipulated by a screw 'l5 andhas the clock mechanism for showing the adjustment position as indicatedin Figures l, 3 and 4. At the outer end the adjustment rocker |2|carries a pivot |23 which pivotally connects with a, vblock |24 slidingin guides |25 extending suitably transversely of a plunger slide 26guided for reciprocation in sliding guides |21 and |28. The guides |25are mounted as part of the slide |26. The plunger slide carries a camfollower |29 at one end which follows the track |30 in a suitable facecam |3|. The cam is driven by a worm |32 on a shaft |33 to a worm gear|34 mounted on the cam. A motor |35 drives the shaft ,I 33 throughsuitable speed reduction as shown in Figure 3.

' In operation it will be seen that the drive turns the cam |3| whichmoves all of the plunger slides for the different pistons in accordancewith the predetermined out-of-phase relationship of the cam tracks |30.For example, if there are two pumps having common inlet and outlet, thecams will be substantially 180 out of phase, `and if there are threepumps, they will be substantially 120 out of phase, not for the momentconsidering the overlap. Each plunger slide will move the correspondingrocker back and forth and the rocker swinging about the pivot |22 willreciprocate the corresponding piston. Motion of the adjustment supportaxially of the screwl will lengthen or shorten the arm of the rockerbetween the pivot and the piston and therefore will 'lengthen or shortenthe throw of the piston.

It will be evident that this construction has the advantage of providingstraight line proportional relationship between the adjustment supportmotion and the pump stroke. The direction of adjustment of theadjustment support is along a line which maintains the same angularrelation with respect to each piston or other pumping element for anyadjustment at at least one corresponding position in the stroke of allpumping elements (actually in this case for every position where thepumping elements are operating side by side in the same direction).Alsoin this form as in the main form the mechanism during adjustment ofthe stroke maintains an invariable relation ,between the speed of eachelement at one part vof the stroke and the speed at every other part ofthe stroke, so that the delivery curve is uniform at all times, insteadof being uniform for only one adjustment as in the prior art.

The num-ber of pumping units making up the constant delivery pump willvary, Figure 1l illustrating two such units |36 and |31 having a commoninlet connection |38 and a common outlet connection |39, so that theinlet is drawn from the same source and the outlet is discharged to thesame source. f

The pumping elements will normally be pistons 94 as shown, but asindicated in Figure l2 the invention may employ some other type ofreciprocating pumping element such as a bellows 94 as shown in Figure12.

In view of our invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of ourinvention without copying the structure shown, and we, therefore, claimall such insofar as they fall within the reasonable spirit and scope ofour claims.

, Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

1. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, a drive, cammeans turned by the drive, followers engaging the cam means andrespectively at different portions of the pump cycle, connecting rodscarrying the followers and guided for reciprocation, pivoted crankblocks interconnected with and swung by the connecting rods, crossheadsreciprocating and connected with the individual elements, sliding blocksslidable in the crossheads transversely to the direction of crossheadmotion, followers making pivotal interconnection between the Aslidingblocks and the crank blocks and means for adjusting the sliding blocksto change the pivotal connection of the sliding blocks with the crankblocks.

2. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, a drive, cammeans turned by the drive, followers engaging the cam means andrespectively at different portions of the pump cycle, connecting rodscarrying the followers and guided for reoiprocation, pivoted crankblocks interconnected with and swung by the connecting rods, crossheadsreciprocating and connected with the individual reciprocating elements,sliding blocks slidable in the crossheads transversely to the directionof crosshead motion, followers making pivotal interconnection betweenthe sliding blocks and the crank blocks, the sliding blocks havingheads, an adjustment block making sliding interconnection with the headsof both sliding blocks and mechanism for moving the adjustment blocktoward and away from the crosshead to adjust the stroke of both pumps inunison.

y 3. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, a drive. cammeans turned by the drive, followers engaging the cam means andrespectively at different portions of the pump cycle, connecting rodscarrying the followers and guided for reciprocation, pivoted crankblocks interconnected with and swung by the connecting rods, crossheadsreciprocating and connected with the individual reciprocating elements,sliding blocks slidable in the crossheads transversely to the directionof crosshead motion, followers making pivotal interconnection betweenthe sliding blocks and the crank blocks, the sliding blocks havingheads, an adjustment block making sliding interconnection with the headsof both sliding blocks, a screw for moving the adjustment toward andaway from the crossheads and guides for the motion of the adjustmentblock.

4. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, a drive, cammeans turned by the drive, followers engagingthe cam means andrespectively at different portions of the pump cycle, connecting rodscarrying-the followers and guided for reciprocation, pivoted crankblocks interconnected with and swung by the connecting rods, crossheadsreciprocating and connected with the individual reciprocating elements,sliding blocks slidable in the crossheads transversely to the directionof crosshead motion, followers making pivotal interconnection betweenthe sliding blocks and the crank blocks, the sliding blocks havingheads, an adjustment block making sliding interconnection with the headsor" both sliding blocks, guides for the motion of the adjustment block`toward and away from the crossheads, a screw for moving the adjustmentblock, a drive for the screw and an indicator for the adjustmentposition.

5. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, blockspivoted to swing in arcs whose outer ends conform generally to the backand forth motion of the reciprocating elements, means for swinging theblocks back and forth and means for pivotally interconnecting thereciprocating elements with the blocks.

G. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and outlet and having reciprocating elements, blockspivoted to swing in arcs Whose outer ends conform generally to the backand forth motion of the elements, means for swinging the blocks back andforth, means for pivotally interconnecting the elements with the blocksand means for adjusting the pivotal interconnections with respect to thepivots of the blocks.

7. In a constant delivery pump, a pair of reciprocating pumps havingcommon inlet and out" let and having reciprocating elements, blockspivoted to swing in arcs whose outer ends conform generally to the backand forth motion of the elements, means for swinging the blocks back andforth, means for pivotally interconnecting the elements and therespective blocks and common means for adjusting the positions of bothpivotal interconnections with respect to the pivots of the blocks inunison.

8. In a constant delivery pump, a pair of reciprocating pumps arrangedside by side having common inlet and outlet reciprocating elements sideby side and adjacent, the elements being directed in the same direction,crossheads, one for each element guided for reciprocation parallel toone another and in the paths of the elements, interconnections betweenthe respective crossheads and the respective elements, blocks one foreach crosshead swingably pivoted on the same axis transverse to thedirection of motion of the crossheads, pivotal interconnections betweeneach block and the corresponding crosshead at a point remote from thecrosshead pivot and the same on each block, means for adjusting thepositions of the pivotal interconnections between the respective blocksand the crossheads in unison and means for rocking the blocks back andforth, the respective blocks being at opposite positions with respect tothe pump cycle.

9. In a constant delivery pump, a pair of reciprocating pumps arrangedside by side having common inlet and outlet and having reciprocatingelements side by side and adjacent, the elements being directed in thesame direction, crossheads, one for each element guided forreciprocation parallel to one another and in the paths of the elements,interconnections between the respective crossheads and the respectiveelements, blocks one for each crosshead swingably pivoted on the sameaxis transverseto the direction of motion of the crossheads, pivotalinterconnections between each block and the corresponding crosshead at apoint remote from the crosshead pivot and the same on each block, meansfor adjusting the positions of the pivotal interconnections between therespective blocks and the crossheads in uni son, connecting rods forrocking the blocks back and forth and cam means for moving theconnecting rods at respectively opposite positions with respect to thepump cycle.

l0. In a constant delivery pump, a pair of reciprocating pumps arrangedside by side having common inlet and outlet and having reciprocatingelements side by side and adjacent, the elements being directed in thesame direction, crossheads, one for each element guided forreciprocation parallel to one another and in the paths of the elements,interconnections between the respective crossheads and the respectiveelements, blocks one for each crosshead swingably pivoted on the sameaxis transverse to the direction of motion of the crossheads, pivotalinterconnections between each block and the corresponding crosshead at apoint remote from the crosshead pivot and the same on each block, meansfor adjusting the positions of the pivotal interconnections between therespective blocks and the crossheads in unison, connecting rods one foreach pump guided for reciprocation parallel to the direction of motionof the elements, followers interconnecting each connecting rod with oneof the blocks, and a parallel cam drive including a cam track formanipulating the connecting rods back and forth in opposite positionswith respect to the pump cycles.

EMMA ELIZABETH SHEEN,

Co-Eecutor for Estate of Milton Roy Sheen,

Deceased.

ROBERT T. SHEEN. ROYAL BARTLETT SAALFRANK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Sheen Jan. 23, 1945

